My first DIY e-bike

[danielrlee]

I'll get my coat . . .

It's all relative. The hotter builds over at Endless Sphere are reaching the 25-30kW mark.

 

[John84]

Firstly, don't buy a new bike as it'll be a waste of money. As soon as you start to modify it, the warranty will be worthless. You'll need a decent full suspension bike which you should look for used. Even then, you'll struggle to find one with sufficient space to mount such a large battery.

Although it would probably just about do the job, IMO that battery isn't powerful enough for what the motor will really want. Minimum 80A continuous for £1K is a more realistic figure:

https://em3ev.com/shop/em3ev-72v-20s10p-rectangle-battery-pack-24-5ah-29-5ah/?currency=USD

Controller £2-300
Cycle Analyst £160
Suitable bike £500-1000
Miscellaneous costs £200

You should also seriously consider using moped rims & tyres at these power levels, since bicycle wheels & tyres are not built for the task. Add another £300.

Add another £150 for a full face helmet and the same again for additional protective gear.

It all mounts up.

It all sounds a lot more complicated than I thought originally. And I can't find anyone who does conversion/custom e-bikes for a fee.

 

[John84]

Ok, so to get 3000w from your MXUS motor you will need to run it with a min. 50 amp controller. Your battery is spec'd to supply 50amp continuous, great, BUT the cells in the battery are only spec'd to supply 8 amp max. current. This means that you will be maxing that battery out most of the time, it will get hot and fail or catch fire. You need a battery pack made of cells that can deliver 20 amps con. Give Jimmy at BGA a call and he can spec. you a battery that will do the job. Prob. around 1k.

You lost me there. I think I better find a kit that includes the battery, controller and motor so I know they match. So far, I have had some nice suggestions for people on this forum. bikes.ca seems legit so does EMV

 

[tommie]

John, what you`re considering here is entering a world of pain for yourself, not to mention the financial outlay.
Keep it simple, spend £800 - £1k on a straightforward BBSHD conversion with a 17-20aH Battery and you`ll have all the power you need for off-road.
And if it`s speed you`re after gear it accordingly.

 

[Deleted member 4366]

Don't forget to add duty to anything that's bought outside of the EU. That will add at least 20% to the cost of any battery, and probably the controller too.

 

[wheeliepete]

Sorry about that John, it wasn't intentional and I wasn't trying to be a smart arse. The point I was trying to make was the fact that what is written in large print on an ad can be mis-leading, it's the small print that quite often matters the most. Get in touch with Paul or Joseph at EM3EV, both very helpful and not just interested in taking your money.

 

[Deleted member 4366]

You can by a 50cc moped, tax and insurance for a lot less than you can make a high powered electric bicycle, and it's reliability and running costs will be a lot lower too, and it's risk free.

Commuting to work on a 50 mph bicycle will soon get noticed, then reported, ending in your arrest, a big fine and said £3000 bike in the crusher.

 

[danielrlee]

It all sounds a lot more complicated than I thought originally. And I can't find anyone who does conversion/custom e-bikes for a fee.

It's not complicated, but experience counts for a lot.

If you want somebody to build and warranty something like this, add around another £1k.

 

[Kermit]

It all sounds a lot more complicated than I thought originally. And I can't find anyone who does conversion/custom e-bikes for a fee.

You might want to look here:
https://www.facebook.com/CyklonEbike/

 

[Richardab]

@danielrlee

I found these online.

3000w MXUS Rear hub motor : 380 EUR
72v/25AH Battery pack : 650 GBP

Am I missing something? How did you get to £3000? Plus the battery above is triangular and can probably fit in the frame of a standard MTB (which I buy new from Halfords for around £500)

I know very little about e-bikes and e-mtb's but I know a bit about mtb and there is NO WAY I would want to ride a £500 Halfords mtb at 50mph. Thats why these things are over £5k
https://www.specialized.com/gb/en/stories/turbo-kenevo

 

[Nealh]

https://www.hi-powercycles.biz/ aka Xipi bikes in Banbury, Frank there used to be on the forum once-upon-a-time. His 6kw bike is 3k and he does 50mph motorbike kits.

Are you sure you want to be riding 50mph on a bicycle frame !!! Get some decent life insurance for any dependants as road users certainly wont be expecting or anticipating you bowling along.

 

[Nealh]

As for the thread head line most start off with a basic 250/350w kit build and ease in to the unknown and tend to be mostly happy with about 18 - 24 mph as a top speed with pas.

 

[John84]

I should have clarified that I wouldn't even consider doing 50mph or even 40mph on public roads, especially during my daily commute but I'd like to have the speed/power available to use once in a blue moon.

@tommie

That's a very attractive solution. A BBSHD 1000w kit to max out at 40-45mph and a large battery pack for great range.

@wheelepete
No problemo. What I learnt from your post is that I should look into getting a kit that someone knowledgable put together instead of trying to be an alchemist, especially since I am noob.
I will also contact them for a kit and maybe even see if they can do the conversion too.

@d8veh

Either the bike is crushed or I end up in ICU (or both).

@Nealh
I will drop him a line and see if he can put together a "reasonably" powerful bike for me.

Thanks to all for the input.

 

[Deleted member 4366]

Being realistic, BBSHD will get you cruising in the mid 20s with bursts up to 30 mph. Mine was a 52v one and I managed to get it up to 44 mph in favourable conditions by adding a second hub-motor at 22 amps and 52v.

 

[anotherkiwi]

Firstly, don't buy a new bike as it'll be a waste of money. As soon as you start to modify it, the warranty will be worthless. You'll need a decent full suspension bike which you should look for used. Even then, you'll struggle to find one with sufficient space to mount such a large battery.

Although it would probably just about do the job, IMO that battery isn't powerful enough for what the motor will really want. Minimum 80A continuous for £1K is a more realistic figure:

https://em3ev.com/shop/em3ev-72v-20s10p-rectangle-battery-pack-24-5ah-29-5ah/?currency=USD

Controller £2-300
Cycle Analyst £160
Suitable bike £500-1000
Miscellaneous costs £200

You should also seriously consider using moped rims & tyres at these power levels, since bicycle wheels & tyres are not built for the task. Add another £300.

Add another £150 for a full face helmet and the same again for additional protective gear.

It all mounts up.

You forgot the charger dan @ about £87

 

[anotherkiwi]

If you want to go fast you need to remove your major enemy - air resistance.



This is a home made all wood velomobile and the young, fit German guy that designed and built it cruises at 65 km/h on the flat with a top recorded speed of around 92 km/h. Without a motor...

Put any 250/350W mid motor in there with a huge chainwheel (he was running 70-56 last time I read) and you to can go fast on the road.

If you want an electric fun machine for off road: https://www.bultaco.com/en/motos

 

[John84]

If you want to go fast you need to remove your major enemy - air resistance.

View attachment 24279

This is a home made all wood velomobile and the young, fit German guy that designed and built it cruises at 65 km/h on the flat with a top recorded speed of around 92 km/h. Without a motor...

Put any 250/350W mid motor in there with a huge chainwheel (he was running 70-56 last time I read) and you to can go fast on the road.

If you want an electric fun machine for off road: https://www.bultaco.com/en/motos

Looks great. Get a couple of oars and you can sail it down Thames.

 

[spanos]

Looks great. Get a couple of oars and you can sail it down Thames.

Heh that made me chuckle

On the bike point, gotta agree with posters here. I had a Norco A line to try and repair the other day. With a 3k mxus hub and all the stuff. It weighed a simply incredible amount. It simply wasn't a bicycle in any respect. It also didn't work and failed to deliver what the owner wanted. They simply saw more power = better

What the owner actually wanted to achieve was better done via a decent full suss bike with large rotors and a bbshd mid drive . I suspect you want this too but maybe with just a hardtail over a full suss

Cheaper and better in every respect other than playing ebike Top Trumps

And strapping a bbshd into a Halfords cheapo is possible. But why ? you can stick a Porsche engine in an vw beetle but it's rubbish for anything but a drag race. Achieve little, massive cost !

Try and find a bbshd to try . You won't need more. I have a Bbs02b and that is more than enough on my titanium hardtail

 

[anotherkiwi]

Heh that made me chuckle

On the bike point, gotta agree with posters here. I had a Norco A line to try and repair the other day. With a 3k mxus hub and all the stuff. It weighed a simply incredible amount. It simply wasn't a bicycle in any respect. It also didn't work and failed to deliver what the owner wanted. They simply saw more power = better

What the owner actually wanted to achieve was better done via a decent full suss bike with large rotors and a bbshd mid drive . I suspect you want this too but maybe with just a hardtail over a full suss

Cheaper and better in every respect other than playing ebike Top Trumps

And strapping a bbshd into a Halfords cheapo is possible. But why ? you can stick a Porsche engine in an vw beetle but it's rubbish for anything but a drag race. Achieve little, massive cost !

Try and find a bbshd to try . You won't need more. I have a Bbs02b and that is more than enough on my titanium hardtail

A 36v "250" W GSM will do 45-47 km/h on a flat road unrestricted, add a 48v battery it will probably climb hills at 35 km/h (I'll report back when I get the controller sorted).

 

[spanos]

A 36v "250" W GSM will do 45-47 km/h on a flat road unrestricted, add a 48v battery it will probably climb hills at 35 km/h (I'll report back when I get the controller sorted).

Yep, I'm sure it will. I have one with the internal controller on my 29er

But it just eats batteries , the amp draw on my early version is insane

I like the bbs02 way more due to the ability to programme. You want high speed, low torque - no worries. Low speed , high torque - no worries. Both? No worries !

Plus it's just nicererer*


*possibly not an actual word